Mechanical writing instrument



H W. SAMS ET AL |April 29, 1952 MECHANICAL WRITING INSTRUMENT PatentedApr. 29, 1952 MECHANICAL WRITING INSTRUMENT Herbert W. Sams and JohnSherman Smith, Jr.,

Atlanta, Ga., assignors to Scripto, Inc., a corporation of Georgia Thisinvention relates to mechanical writing instruments and moreparticularly to mechanical writing instruments adapted to accommodatemarking elements of relatively large diameter such as crayons and thelike.

The mechanical writing instrument of this invention is of the typecomprising a barrel and a feed mechanism disposed in the barrel forfeeding a marking element to the writing end thereof. An importantfeature of the construction employed according to the present inventionis the manner in which the feed mechanism is assembled with the barrelby a sleeve member engaging the barrel at its upper end and formed toa1- low operating access to the feed mechanism in assembled position. Afurther feature of this construction is an improved form of frictionelement associated with the feed mechanism to restrain retracting motionof the feed mechanism under writing pressure.

As mentioned above, the mechanical writing instrument of this inventionis particularly adapted for use with marking elements of rela tivelylarge diameter. A principal example of such making elements are the softwax base leads known as crayons, and the present invention is describedbelow largely in relation to its embodiment for use with crayon markingelements. The writing instrument of the present invention, however, mayalso be used with other comparable marking elements, and in particularis well suited for use with marking elements of the class characterizedby a ball-type applicator. Marking elements of this type may be insertedand removed at the writing end of the barrel in the usual manner withoutthe necessity for disassembling the barrel when replacement is needed,and the feed mechanism as disposed in the barrel according to thepresent invention allows easy and convenient projection of the ball-typemarking element for writing when desired and retraction for protectionwhen not in use.

The present invention is described further in vdetail below inconnection with the accompanying drawing, in which:

Fig. 1 is a side elevation of a mechanical writing instrument embodyingthe present invention;

Fig. 2 is an enlarged vertical section of the writing instrument;

Fig. 3 is an enlarged detail of the guide tube and clutch assembly asseen from the right side n Fig. 2;

Fig. 4 is a section taken substantially on the line 4-4 in Fig. 2;

. 2 Fig. 5 is a section taken substantially on the line 5 5 in Fig. 2;

Fig. 6 is a side elevation, partly in section,`

showing the manner in which a marking element having a ball-typeapplicator may be used with the writing instrument of the presentinvention; and,

Fig. 7 is an enlarged detail of. a marking element suitable for use asshown in Fig. 6.

Referring iirst to Fig. 1. of the drawing, the barrel of the mechanicalwriting instrument of the present invention is shown at I0. The barrelI0 is preferably formed of a suitable plastic material, and is taperedat its lower portion to form a writing tip II from which a markingelement may be fed, such as thecrayon represented at I2.

The upper end of the barrel I0 is tted with a sleeve member I3 by whichthe feed mechanism is retained in assembled relation with the barrel asdescribed more in detail below. The sleevev member I3 is formed to allowprojection of an operating cap I4 at the upper end of the barrel I0 for.manipulation to operate the feed mechanism. Also, ,thisr sleeve memberI'3 serves the further purpose of securing a pocket clip I5 in place onthe barrel I0 (compare Figs. 2 and 5).

The feed mechanism referred to above is illustrated more in detail inFig. 2 of the drawing, and as shown comprises a longitudinally slottedguide tube I6, and a clutch assembly I1 which receives and holds themarking element I2 for -feeding to the writing end of the barrel I0. Theclutch assembly I'I comprises a grip sleeve I8 and an associatedpropelling element I9A (compare Fig. 3).

The writing end portion of the barrel I0 is formed with a bore 20adapted to accommodate the marking element I2, the bore 20 having adiameter such that the marking element l2 is closely supported forfeeding from the writing tip IIV of the barrel I0. Beyond the bore 20,the barrel ID is also formed with upwardly facing shoulders 2| and 22providing further coaxial bores 23 and 24, and with internal screwthreads 25 for the major portion of its remaining length.

The ends of the above mentioned longitudinally slotted guide tube I6 ispositioned in the barrel I0 bythe shoulder 22, the lower end of theguide tube I6l being received by the bore 24, and as thus arranged theguide tube I6 is free for rotation in the barrel I0. This guide tube I6is provided in a length sucient to project from the upper end of thebarrel I0 to carry the operating cap I4. The operating cap. I4 is formedwith an internal lug portion 26 which is adapted to fit the longitudinalslot in the guide tube I6 and thus is provided a keyed engagementallowing rotation of the guide tube I6, and consequent operation of thefeed mechanism, from the cap I4. The operating cap I4 is generallycylindrical in shape,` and is formed at its base with an enlargedshoulder portion or flange 21 adapted to rest and turn on the upper endof the barrel I0.

As previously mentioned, the sleeve member I3 is adapted to allowprojection of the operating cap I4 and the guide tube I6 at the upperend of the barrel In, the sleeve member I3 being formed with an annularshoulder 28 allowing clearance for the main body vof the operating capI4 but fitting the enlarged shoulder portion 21 in retaining relation asshown in Fig. 2. The sleeve member I3 is further formed with screwthreads 29 adapted for engagement with screw threads 30 formedexternally at the upper end of barrel III, so that when the sleevemember I3 is in place the feed mechanism is Yretained assembled inrelation with the barrel I between the shoulder 22 at the writing end ofthe barrel I0 and the annular shoulder 28 on the sleeve member I3.According to this arrangement only a single retaining means, namely, thesleeve member I3, is required for the entire assembly of the writinginstrument of the present invention, which provides important structuraland manufacturing advantages.

VThe clutch assembly I1 associated with the guide tube I6 in the feedmechanism employed according to the present invention is disposed in theguide I6 for translation longitudinally of the barrel I0 during feedingmovement. To effect this translation the propelling element I9 of theclutch assembly I1 which is formed with a cylindrical head portion 3Iproportioned for a sliding fit in the bore of guide tube I6, is furtherformed at this head portion 3I with a projecting face portion 32extending through the longitudinal slot of the guide tube I6 and shapedwith thread segments 33 adapted for engagement with the internal screwthreads 25 in thebarrel I0. The internal screw threads 25 are preferablyformed as multiplel threads, suitably triple threads as indicated inFig. 4, to provide desirable pitch characteristics, and the threadsegments33 may accordingly be arranged to mesh with the multiplethreadsprovided.

The propelling element I9 also comprises a shank portion 34 whichextends in reduced diameter for association with the grip sleeve I8. Thegrip sleeve I 8 is slotted lengthwise in varying congurations. At itslower extending end portion a narrow slit 3'5 is formed to providesufficient spring action for gripping the upper end of the markingelement I2 to be fed. Beyond the narrow slit 35, a wider guide slot 36is formed which extends longitudinally toward .the upper end of the gripsleeve I8 to an angled continuation which is biased at about 45 degreesas shown at 31'. A flange 38 is formed along the lower edgeof thisangled continuation 31 in a 'width proportioned to fit for slidingmovement in the longitudinalvslot of the guide tube I6. The upper end ofthe grip sleeve I8 is formed with a further slot 39 of suiiicient widthto allow assembly on the shank 34 of the propelling element I9, butdisplaced circumferentially with respect to the guide slot 3E and angledcontinuation 31 so as to prevent disengagement of the propelling4element I9 from the grip sleeve I8 during operation of thefeedmechanism.

The propelling element I9 is associated for operation with the gripsleeve I8 by means of a lug 48 formed on the shank portion 34 of thepropelling element I9. This lug 40 is shaped to operate in the guideslot 36 and angled continuation 31 of the grip sleeve I8, having a widthadapted to iit the guide slot 33 and a length accommodated in the angledcontinuation 31, and being formed with a pointed lower face, as shown at4I, presenting a contact surface biased in correspondence with theflange 38 formed I along'the lower edge of the angled continuation 31.The lug 40 extends with the flange 38 into the longitudinal slot of theguide tube I6 as shown in Fig. 2, and during normal operation of thefeed mechanism the propelling element I9 and grip sleeve I8 are thusheld in fixed relation, the lug 40 being contained between the flange 38and the upper edge of the angled continuation 31 during advancement orretraction of the marking element I2 carried by the grip sleeve I8, andthe disposition of the lug 40 and flange 38 in the longitudinal slot ofthe guide tube I6 serving to retain the lug 4U in the angledcontinuation 31 in contact with the ange 38 (compare Fig. 3).

The upward extent of movement of the clutch assembly I1 in the guidetube I6 is determined by ears 42 struck inwardly adjacent thelongitudinal slot of the guide tube I6 near the upper end thereof toengage the cylindrical head portion 3| of the propelling element I9 andact as a stop against further upward movement of the clutch assembly I1(compare Fig. 6). The ears 42 are located in the guide tube I6 so as toprovide for properaccommodation in relation to the writing tip II of thebarrel IU of the original length of a marking element I2 to be used inthe writing instrument, and with the clutch assembly I1 in positionagainst the ears 42, the writingy instrument may be charged with amarking element I2 in a length extending for a major portion of thelength of the barrel I0. With the clutch assembly I1 thus in positionagainst the ears 42 and charged with a marking element I2, feeding ofthe marking Aelement I2 from the writing end of the barrel I0 maybeeffected from the operating cap I4, rotation of the operating cap I4 inone direction resulting in corresponding rotation of the guide tube I6and consequent feeding movement of the clutch assembly I1'by virtue ofthe engagement of 'the projecting face portion 32 with the internalscrew threads 25 in the barrel I0, and rotation of the operating cap I4in the opposite direction resulting in retraction ofthe marking elementlI2.

The downward extent of movement of the clutch assembly I1 is determinedby the shoulder configuration 2I formed in the writing end of the barrelID. In full downward position, which corresponds as shown in Fig. 2 withsubstantial exhaustion of a marking element I2 functioning by attritionsuch as a crayon, the grip sleeve I8 is received in the bore 23 -tobottom on the shoulder configuration 2I so that' further feedingmovement is arrested. When this position is reached, the propelling.element I9 is disposed in relation to the internal screw threads 25 inthe barrel I0 so that it still has a remaining extent of downwardtravel. The clutch assembly I1 is arranged for operation to expel thespent marking element I2 during this remaining extent of downward travelof the propelling elementv I9.'

For this purpose the longitudinal slot in the guide tube I6 isy relievedor notched as shown at 43 in Fig. 3 to provide clearance for the flange'asoaotif 5s 38 so that the grip sleeve I8 may be rotated. With the gripsleeve I8 freed for rotation in this manner, further downward movementof the propelling element I9 causes such rotation due to the fact thatthe pointed lower face 4I of the lug 48 acts in the nature of a cam topush the flange 38 to one side, and thus transfers the lug 4I), from theangled continuation 31 into alignment with the guide slot 3S. Thepropelling element I9 may accordingly continue for its full extent ofdownward movement in the guide slot 38, and as the grip sleeve I8 isbottomed on the shoulder configuration 2 I, the extending end of theshank portion 34 of the propelling element I9 will strip the markingelement I2 from the grip sleeve I8 and eject it from the bore 20 at thewriting end of the barrel I during this continued downward movement.Upon retraction of the propelling element I9 following ejection of themarking element I2, the lug 48 makes contact with the upper edge of theangled continuation 3'! causing retraction of the grip sleeve I8 aswell, so that the flange 38 is returned from the notch 43 to thelongitudinal slot in the guide tube I6 and the clutch assembly I'I isagain disposed for normal operation.

As previously mentioned, a further important feature of the arrangementof the feed mechanism according to the present invention is an improvedform of friction element 44 associated with the feed mechanism torestrain retracting motion under writing pressure. The friction element44 is adapted for assembly with the guide tube I6, and is disposedinside the upper end portion of the barrel II) beyond the screw threads25, the barrel II] being formed with a bore 45 at this point to receivethe friction element 44. For assembly with the guide tube I6 thefriction element 44 is formed with a grooved portion 4t shaped for keyedengagement in the longitudinal slot of the guide tube I8 (see Fig. 5).The friction element 44 further comprises arcuate arm portions 41extending from the grooved portion 45 for frictional engagement in thebore 45 with the barrel I0. These extending arm portions 4'! terminatein at portions 48 formed inwardly to engage the back of the guide tubeI6 and thereby position the grooved portion 46 in the longitudinal slotof the guide tube I6 and support the extending arm portions 41 infrictional engagement with the barrel Ill. This form of frictionalelement 44 is easily associated with the feed mechanism, and while itprovides particularly effective braking action for the feed mechanism,it offers no interference whatever in taking down and assemblying thefeed mechanism in the barrel I0.

In Fig. 6 of the drawing, the adaption of the writing instrument of thepresent invention for use with marking elements of the classcharacterized by a ball-type applicator is illustrated. Marking elementsof this sort are constructed for use with a so-called dense ink and arewell known and commonly available so that no detailed description isneeded here. A suitable balltype marking element 49 for use according tothe present invention is shown in Fig. 7. Briefly described, thismarking element comprises a tubular body portion 50 forming an inkreservoir and a ball-type applicator I carried at the forward end of thebody portion 50. The marking element 49 is provided in a lengthproportioned so that the ball-type applicator 5I will be disposed justinside the forward end of the bore 20 at the writing end of the barrelIllv with the rear end of the body portion 50 inserted in the gripsleeve I8- tact. For use in writing, however, the marking.

element is easily and quickly projected at the; writing end of thebarrel I0 by manipulation of the operating cap I4 in the usual manner.Moreover, the marking element 4S may be replaced when its ink supply hasbeen expended just as an ordinary lead or crayon marking element wouldbe, so that. a rell supply of the marking elements 49 may be providedfor usewith a writing instrument constructed according to the presentinvention in the samevmanner that has long been common with lead andcrayon marking elements.

We claim:

1. A mechanical writing instrument comprising a barrel, a feed mechanismincluding a rotatable, longitudinally slotted, guide tube disposed insaid barrel for feeding a marking element to the writing end of saidbarrel, and a friction element having a key portion formed forengagement in the longitudinal slot in said guide tube and arcuate armportions extending from said key portion for frictional engagementinteriorly with said barrel for restraining rotation of said guide tubeunder writing pressure.

2. A mechanical writing instrument as dened in claim 1 and furthercharacterized in that the extending arcuate arm portions of saidfriction element terminate in iiat portions formed inwardly to engagesaid guide tube and thereby position said key portion of said frictionelement in the longitudinal slot in said guide tube and support saidextending arm portions in frictional engagement with said barrel.

3. A mechanical writing instrument comprising a barrel, a feed mechanismincluding a rotatable, longitudinally slotted, guide tube removablybottomed in said barrel for feeding a marking element to the writing endthereof, the guide tube of said feed mechanism projecting for operationfrom the upper end of said barrel, an operating cap detachably assembledon the projecting portion of said guide tube by keyed engagement withthe longitudinal slot thereof and adapted to rest for rotation on theupper end of said barrel, and a sleeve member detachably engaging saidbarrel and said operating cap and constituting the sole assembly meansby which said feed mechanism and operating cap are retained in assembledrelation and in operating position with respect to said barrel.

4. A mechanical writing instrument comprising a barrel having a bore ofsuliicient size at the writing end portion thereof to receive markingelements of relatively large diameter such as crayons and ball-typeapplicators, said barrel being formed with a further coaxial bore ofstill larger size for the major portion of its remaining length and withat least one circumferential shoulder between said first and secondmentioned bores, a feed mechanism including a rotatable, longitudinallyslotted, guide tube removably disposed in the second mentioned bore ofsaid barrel for feeding a marking element through said rst mentionedbore, said guide tube being bottomed in said barrel on saidcircumferential shoulder and projecting for operation from the upper end7 of. said barrel, ari operating cap detachably keyed on; the projectingportion ofsaid guide tube by engagement with the` longitudinal slotthereof and formed at its base with an outwardly directed ilange portionadaptedA to rest for rotation on the upper end of said barrel, and asleeve member detachably engaging said barrel adjacent said upperend,.said sleeve member being formed with an inwardly directed flangeportion adaptedto t over theange portion of said operating cap andthereby detachably engage .said cap also as the sole assembly means bywhich said feed mech'- anism and cap are retained in assembledA re-Vlation and in `operating .position with `respect to said barrel whileallowing access to said'operating capfor manipulation to operate saidfeed mechanism. .1 J i HERBERT W. SAMS. Y.

`JOHN SHERMAN SMITH. JR.vr

REFERENCES CITED UNITED STATES PATENTS Number Name Date 955,617 TuckerApr. 19, 1910 1,410,666 Fischer xMar. 28, 1922 1,441,000 Keeran Jan. 2.1923 1,589,260 Steian June 15, 1926 1,674,357 Fleming -:June 19, 19282,035,225 Esterow Mar. 24, 1936 2,129,655 DeWitt Sept. 13, 1938

